Created attachment 2679 [details] a screen copy of the message In our Koha, we have created several status for not for loan items. These status are in a list of authorized values (0 : authorized loan, other values = not authorized loan). You can force the issuing of a not for loan item. When the value is "1" (normal value for not for loan), you have a message, you force the issuing, and after every thing go right. If the notforloan value is different (< 1), you can force the issuing, but after you have the same message for forcing the issuing everytime even for authorized items, until the unauthorized item is back.
This bug seems to be not easy to reproduct !
I have checked in current master (3.12beta) - items with notforloan values > 1 ask for confirmation on checkout. Checking out other itmes after that behaves normally.